Curtain Metreage with a 46 cm Repeat and a Shrinking Cotton Print

Step 1 - width per curtain

• Two pairs = 4 curtains. Window 210 cm ÷ 4 = 52.5 cm finished width per curtain.
• At 2.25 fullness: 52.5 × 2.25 = 118.1 cm flat cut width.
• Usable fabric width = 137 − (2 × 2.5 side turnings) = 132 cm. Since 118.1 < 132, one fabric width per curtain; 4 drops in total. No horizontal seam matching is needed, but the 32 cm horizontal repeat must still be centred on each drop.

Step 2 - cut length per drop

• 240 finished + 10 heading + 10 hem = 260 cm.
• Vertical repeat 46 cm: 260 ÷ 46 = 5.65 → 6 repeats = 276 cm per drop. Cutting shorter would break the pattern at the hem.

Step 3 - total

• 4 drops × 276 cm = 1,104 cm = 11.04 m.
• Add one extra repeat (46 cm) to position the first drop on the repeat and align all four: 11.04 + 0.46 = 11.5 m.
• Stock is 11 m, so order at least 0.5–1 m more (buy 12 m to allow for a skewed or damaged repeat).

Step 4 - shrinkage

• 3% of 276 cm ≈ 8.3 cm per drop. Either add 3% (276 → 284 cm, rounded up to 7 repeats = 322 cm per drop, i.e. 13.4 m) or pre-wash/sponge the 11 m in the workroom and cut at 276 cm. Pre-shrinking is the cheaper answer and fits the ten-day deadline.

Plain fabric comparison

• Cut length would simply be 260 cm + about 5 cm wastage = 265 cm per drop; 4 × 2.65 m = 10.6 m, versus 11.5 m for the print - the repeat costs roughly 1 m, about 8%, plus the risk of a mis-matched drop.
• The loss is not the repeat itself but the rounding up from 260 to 276 cm (16 cm per drop) plus one whole repeat for aligning the set.

If two widths were needed per curtain

• Each curtain would need 8 panels, 8 × 276 cm = 22.1 m before matching.
• The horizontal repeat of 32 cm would then become critical: panels must be joined so the print matches at the seam, and the seam must be positioned where it is least visible (towards the outer edge, not the leading edge).
• Extra fabric for horizontal matching is normally one full horizontal repeat per join, and a half-drop repeat would double the allowance again.
• The alternative to check first is railroading (turning the fabric 90° so the 137 cm width becomes the drop); it removes all vertical matching here but would limit the drop to the fabric width - not usable for a 240 cm drop.

Advice

• The 3% first-wash shrinkage is a stated property of the cotton face fabric. After the curtains are made up at 2.25 fullness and pleated, a home wash will shrink the face but not the polyester lining, so the lining will bag and the pleats will drop. The safest advice is dry clean, or a very gentle cold hand wash with no spin if the client insists.
• If home washing is unavoidable, the fabric must be pre-shrunk before making up, and the pleats re-set (spray, comb into pleats, tie and dry flat) after every wash.

Care label content and reasoning

• Dry clean, P symbol - preserves pleat memory and avoids differential shrinkage against the lining.
• If washable: machine/hand wash 30–40 °C, mild, because cotton print dyes bleed at higher temperatures and mechanical action distorts pleats.
• Do not bleach - chlorine yellows cotton and destroys print dyes.
• Do not tumble dry - heat and tumbling crush the pleats and add relaxation shrinkage.
• Line dry in shade, hang by the heading so the drop dries straight.
• Warm iron, max 150 °C, on the reverse, avoiding the pleat edges so they do not flatten and shine.
• Wash dark colours separately for the first few washes, because unfixed print dye may bleed.

Reasoning: the label must describe what the made-up article can survive, not merely what the greige fabric tolerates; a label promising machine washing at 60 °C would be a false claim and a returns risk.